Pentagun is nowhere against the M500. I was using it since I bought it, and I have to say, that if you flank the enemy with it, no one survives that. On Chertanovo LZ, I have flanked the enemy 2 times. I only needed 5 slugs, to kill 5 enemy. It's a very good, one-shot kill shotgun, and can be used very well, in a face-to-face combat, or with flanking purposes. I am called a hacker once, and someone recorded me playing, because he thought I was hacking. Needless to say, I killed the whole team 2 times, to hold them up as long as I could, until my team captured the point.
P.S.: Shotguns do not need to be nerfed. They are as good as now, the damage, the recoil, the handling and the accuracy is perfectly set, the gun is not OP, it's just the user who uses it well.